The optical capacity of LED light sources has undergone a development, making their use appear of interest for general lighting purposes. LED light sources are distinguished by their efficiency and, whilst provided the operating conditions are observed, by particular reliability. Their light-radiation characteristic as well as the operating conditions to be observed do, however, basically differ from those of conventional illuminants, such as, for example, incandescent bulbs, fluorescent tubes or gas-discharge lamps, so that it appears that existing luminaire constructions can only be retrofitted at considerable expense.